As an outdoor heat exchanger used in a heat pump system for a vehicle air-conditioning and the like, a sub-cool system condenser is disclosed, including a main core (condenser core) portion for condensing a refrigerant by heat exchange with air, a receiver tank into which the refrigerant having flowed through the main core portion is made to flow, and a sub-cool core portion for over-cooling and liquefying a gas/liquid mixed refrigerant having flowed through the receiver tank by heat exchange with the air (see Patent Literature 1, for example).
Each of the main core portion and the sub-cool core portion is constituted by a plurality of tubes causing a pair of header tanks communicate with each other, arranged at an interval in a state in parallel with each other and a fin arranged between the adjacent tubes, for example.